Method and apparatus for performing cell (re)selection in wireless communication systems

ABSTRACT

A method performed by a UE for wireless communications is provided. The method includes receiving first other system information from a base station, other system information including system information other than minimum system information broadcast by the base station; determining whether an SUL-related factor is present in the first other system information; transmitting an RRC system information request message to the base station in response to determining that the SUL-related factor is absent in the first other system information; and determining a minimum required received level based on the SUL-related factor in a case that the UE receives the SUL-related factor in second other system information from the base station; and determining a cell selection criterion based on the minimum required received level.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application is a continuation application of U.S. patentapplication Ser. No. 16/446,402, filed on Jun. 19, 2019, entitled“METHOD AND APPARATUS FOR PERFORMING CELL (RE)SELECTION IN WIRELESSCOMMUNICATION SYSTEM,” which claims the benefit of and priority to U.S.Provisional Patent Application Ser. No. 62/688,192, filed on Jun. 21,2018, entitled “System Information Content Design.”. The contents of allof the above-named applications are hereby fully incorporated herein byreference for all purposes.

FIELD

The present disclosure generally relates to wireless communications and,more particularly, to methods and apparatuses for performing a cell(re)selection procedure in a wireless communication system.

BACKGROUND

Various efforts have been made to improve different aspects of wirelesscommunications (e.g., data rate, latency, reliability, mobility, etc.)for the next generation (e.g., 5G New Radio (NR)) wireless communicationsystems. For example, in the next generation wireless communicationsystems, the distribution of system information may be a target forenergy efficiency, fast system access, flexible deployment, etc.However, the design of system information content in the informationblocks needs to consider the usage of such system information contentand how the information blocks are distributed. Furthermore, to achieveflexibility and energy efficiency, the minimum system information needsto be structured to be as compact as possible.

SUMMARY

The present disclosure is directed to methods and apparatuses forperforming a cell (re)selection procedure in a wireless communicationsystem.

According to a first aspect of the present disclosure, a User Equipment(UE) is provided. The UE includes one or more non-transitorycomputer-readable media having computer-executable instructions embodiedthereon and at least one processor coupled to the one or morenon-transitory computer-readable media. The at least one processor isconfigured to execute the computer-executable instructions to receive aminimum required received level factor in a System Information BlockType 1 (SIB1) from a base station, determine whether a firstSupplementary Uplink (SUL)-related factor is present in the SIB1, obtaina first minimum required received level from the minimum requiredreceived level factor, when the first SUL-related factor is not presentin the SIB1, determine a first cell selection criterion based on thefirst minimum required received level, and perform cell selection basedon the first cell selection criterion.

According to a second aspect of the present disclosure, a base stationis provided. The base station includes one or more non-transitorycomputer-readable media having computer-executable instructions embodiedthereon and at least one processor coupled to the one or morenon-transitory computer-readable media. The at least one processor isconfigured to execute the computer-executable instructions to transmit aminimum required received level factor in a SIB1, receive a RadioResource Control (RRC) system information request message from a UE, andtransmit an SUL-related factor in other system information in responseto receiving the RRC system information request message.

According to a third aspect of the present disclosure, a method ofwireless communication is provided. The method includes receiving, by aUE, a minimum required received level factor in a SIB1 from a basestation, determining, by the UE, whether a first SUL-related factor ispresent in the SIB1, obtaining, by the UE, a first minimum requiredreceived level based on the minimum required received level factor, whenthe first SUL-related factor is not present in the SIB1, determining, bythe UE, a first cell selection criterion from the first minimum requiredreceived level, and performing, by the UE, cell selection based on thefirst cell selection criterion.

According to a fourth aspect of the present disclosure, a UE isprovided. The UE includes one or more non-transitory computer-readablemedia having computer-executable instructions embodied thereon and atleast one processor coupled to the one or more non-transitorycomputer-readable media. The at least one processor is configured toexecute the computer-executable instructions to receive first othersystem information from a base station, other system informationincluding system information other than minimum system informationbroadcast by the base station; determine whether an SUL-related factoris present in the first other system information; transmit an RRC systeminformation request message to the base station in response todetermining that the SUL-related factor is absent (or is not present) inthe first other system information; determine a minimum requiredreceived level based on the SUL-related factor in a case that the UEreceives the SUL-related factor in second other system information fromthe base station; and determine a cell selection criterion based on theminimum required received level.

In some implementations of the fourth aspect of the present disclosure,the at least one processor is further configured to execute thecomputer-executable instructions to receive the SUL-related factor inintra-frequency cell reselection information in a System InformationBlock 2 (SIB2) of the second other system information from the basestation.

In some implementations of the fourth aspect of the present disclosure,the at least one processor is further configured to execute thecomputer-executable instructions to perform an intra-frequency cellreselection procedure based on the cell selection criterion.

In some implementations of the fourth aspect of the present disclosure,the at least one processor is further configured to execute thecomputer-executable instructions to receive the SUL-related factor ininter-frequency cell reselection information in a System InformationBlock 4 (SIB4) of the second other system information from the basestation.

In some implementations of the fourth aspect of the present disclosure,the at least one processor is further configured to execute thecomputer-executable instructions to perform an inter-frequency cellreselection procedure based on the cell selection criterion.

In some implementations of the fourth aspect of the present disclosure,the at least one processor is further configured to execute thecomputer-executable instructions to receive the SUL-related factor ininter-Radio Access Technology (inter-RAT) cell reselection informationin the second other system information from the base station.

In some implementations of the fourth aspect of the present disclosure,the at least one processor is further configured to execute thecomputer-executable instructions to perform an inter-RAT cellreselection procedure based on the cell selection criterion.

According to a fifth aspect of the present disclosure, a methodperformed by a UE for wireless communications is provided. The methodincludes receiving first other system information from a base station,other system information including system information other than minimumsystem information broadcast by the base station; determining whether anSUL-related factor is present in the first other system information;transmitting an RRC system information request message to the basestation in response to determining that the SUL-related factor is absent(or is not present) in the first other system information; determining aminimum required received level based on the SUL-related factor in acase that the UE receives the SUL-related factor in second other systeminformation from the base station; and determining a cell selectioncriterion based on the minimum required received level.

In some implementations of the fifth aspect of the present disclosure,the method further includes receiving the SUL-related factor inintra-frequency cell reselection information in a SIB2 of the secondother system information from the base station.

In some implementations of the fifth aspect of the present disclosure,the method further includes performing an intra-frequency cellreselection procedure based on the cell selection criterion.

In some implementations of the fifth aspect of the present disclosure,the method further includes receiving the SUL-related factor ininter-frequency cell reselection information in a SIB4 of the secondother system information from the base station.

In some implementations of the fifth aspect of the present disclosure,the method further includes performing an inter-frequency cellreselection procedure based on the cell selection criterion.

In some implementations of the fifth aspect of the present disclosure,the method further includes receiving the SUL-related factor ininter-RAT cell reselection information in the second other systeminformation from the base station.

In some implementations of the fifth aspect of the present disclosure,the method further includes performing an inter-RAT cell reselectionprocedure based on the cell selection criterion.

According to a sixth aspect of the present disclosure, a base station isprovided. The base station includes one or more non-transitorycomputer-readable media having computer-executable instructions embodiedthereon and at least one processor coupled to the one or morenon-transitory computer-readable media. The at least one processor isconfigured to execute the computer-executable instructions to transmitfirst other system information to a UE, causing the UE to determinewhether an SUL-related factor is present in the first other systeminformation, other system information including system information otherthan minimum system information broadcast by the base station; cause theUE to transmit an RRC system information request message to the basestation by not including the SUL-related factor in the first othersystem information; receive the RRC system information request messagefrom the UE; transmit second other system information including theSUL-related factor to the UE in response to receiving the RRC systeminformation request message; and cause the UE to determine, based on theSUL-related factor, a minimum required received level for determining acell selection criterion.

In some implementations of the sixth aspect of the present disclosure,the SUL-related factor is transmitted in intra-frequency cellreselection information in the second other system information.

In some implementations of the sixth aspect of the present disclosure,the second other system information includes a SIB2 that includes theintra-frequency cell reselection information.

In some implementations of the sixth aspect of the present disclosure,the SUL-related factor is transmitted in inter-frequency cellreselection information in the second other system information.

In some implementations of the sixth aspect of the present disclosure,the second other system information includes a SIB4 that includes theinter-frequency cell reselection information.

In some implementations of the sixth aspect of the present disclosure,the SUL-related factor is transmitted in inter-RAT cell reselectioninformation in the second other system information.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. Variousfeatures are not drawn to scale. Dimensions of various features may bearbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a timing diagram illustrating a split of SIB1 content, inaccordance with example implementations of the present disclosure.

FIG. 2 is a signaling flow diagram illustrating a signaling flow betweena UE and a cell, in accordance with example implementations of thepresent disclosure.

FIG. 3 is a signaling flow diagram illustrating a signaling flow betweena UE and a cell, in accordance with example implementations of thepresent disclosure.

FIG. 4 is a flowchart for a method of receiving system information, inaccordance with example implementations of the present disclosure.

FIG. 5 is a block diagram illustrating a node for wirelesscommunication, in accordance with various aspects of the presentapplication.

DETAILED DESCRIPTION

The following description contains specific information pertaining toexample implementations in the present disclosure. The drawings in thepresent disclosure and their accompanying detailed description aredirected to merely example implementations. However, the presentdisclosure is not limited to merely these example implementations. Othervariations and implementations of the present disclosure will occur tothose skilled in the art. Unless noted otherwise, like or correspondingelements among the figures may be indicated by like or correspondingreference numerals. Moreover, the drawings and illustrations in thepresent disclosure are generally not to scale and are not intended tocorrespond to actual relative dimensions.

For the purpose of consistency and ease of understanding, like featuresare identified (although, in some examples, not shown) by numerals inthe example figures. However, the features in different implementationsmay be differed in other respects, and thus shall not be narrowlyconfined to what is shown in the figures.

The description uses the phrases “in one implementation,” or “in someimplementations,” which may each refer to one or more of the same ordifferent implementations. The term “coupled” is defined as connected,whether directly or indirectly through intervening components, and isnot necessarily limited to physical connections. The term “comprising,”when utilized, means “including, but not necessarily limited to”; itspecifically indicates open-ended inclusion or membership in theso-described combination, group, series, and the equivalent. Theexpression “at least one of A, B and C” or “at least one of thefollowing: A, B and C” means “only A, or only B, or only C, or anycombination of A, B and C.”

Additionally, for the purposes of explanation and non-limitation,specific details, such as functional entities, techniques, protocols,standard, and the like are set forth for providing an understanding ofthe described technology. In other examples, detailed description ofwell-known methods, technologies, systems, architectures, and the likeare omitted so as not to obscure the description with unnecessarydetails.

Persons skilled in the art will immediately recognize that any networkfunction(s) or algorithm(s) described in the present disclosure may beimplemented by hardware, software or a combination of software andhardware. Described functions may correspond to modules which may besoftware, hardware, firmware, or any combination thereof. The softwareimplementation may comprise computer-executable instructions stored oncomputer-readable medium such as memory or other type of storagedevices. For example, one or more microprocessors or general-purposecomputers with communication processing capability may be programmedwith corresponding executable instructions and carry out the describednetwork function(s) or algorithm(s). The microprocessors orgeneral-purpose computers may be formed of Application-SpecificIntegrated Circuits (ASICs), programmable logic arrays, and/or using oneor more Digital Signal Processor (DSPs). Although some of the exampleimplementations described in this specification are oriented to softwareinstalled and executing on computer hardware, nevertheless, alternativeexample implementations implemented as firmware or as hardware orcombination of hardware and software are well within the scope of thepresent disclosure.

The computer-readable medium includes but is not limited to RandomAccess Memory (RAM), Read-Only Memory (ROM), Erasable ProgrammableRead-Only Memory (EPROM), Electrically Erasable Programmable Read-OnlyMemory (EEPROM), flash memory, Compact Disc Read-Only Memory (CD-ROM),magnetic cassettes, magnetic tape, magnetic disk storage, or any otherequivalent medium capable of storing computer-readable instructions.

A radio communication network architecture (e.g., a Long-Term Evolution(LTE) system, an LTE-Advanced (LTE-A) system, an LTE-Advanced Prosystem, or a 5G NR Radio Access Network (RAN)) typically includes atleast one base station, at least one UE, and one or more optionalnetwork elements that provide connection towards a network. The UEcommunicates with the network (e.g., a Core Network (CN), an EvolvedPacket Core (EPC) network, an Evolved Universal Terrestrial Radio Accessnetwork (E-UTRAN), a Next-Generation Core (NGC), a 5G Core (5GC), or aninternet), through a RAN established by one or more base stations.

It should be noted that, in the present application, a UE may include,but is not limited to, a mobile station, a mobile terminal or device, ora user communication radio terminal. For example, a UE may be a portableradio equipment, which includes, but is not limited to, a mobile phone,a tablet, a wearable device, a sensor, a vehicle, or a Personal DigitalAssistant (PDA) with wireless communication capability. The UE isconfigured to receive and transmit signals over an air interface to oneor more cells in a radio access network.

A base station may be configured to provide communication servicesaccording to at least one of the following Radio Access Technologies(RATs): Worldwide Interoperability for Microwave Access (WiMAX), GlobalSystem for Mobile communications (GSM, often referred to as 2G), GSMEnhanced Data rates for GSM Evolution (EDGE) Radio Access Network(GERAN), General Packet Radio Service (GPRS), Universal MobileTelecommunication System (UMTS, often referred to as 3G) based on basicwideband-code division multiple access (W-CDMA), high-speed packetaccess (HSPA), LTE, LTE-A, eLTE (evolved LTE, e.g., LTE connected to5GC), NR (often referred to as 5G), and/or LTE-A Pro. However, the scopeof the present application should not be limited to the above-mentionedprotocols.

A base station may include, but is not limited to, a node B (NB) as inthe UNITS, an evolved node B (eNB) as in the LTE or LTE-A, a radionetwork controller (RNC) as in the UMTS, a base station controller (BSC)as in the GSM/GERAN, a ng-eNB as in an E-UTRA base station in connectionwith the 5GC, a next generation Node B (gNB) as in the 5G-RAN, and anyother apparatus capable of controlling radio communication and managingradio resources within a cell. The base station may connect to serve theone or more UEs through a radio interface to the network.

The base station is operable to provide radio coverage to a specificgeographical area using a plurality of cells forming the radio accessnetwork. The base station supports the operations of the cells. Eachcell is operable to provide services to at least one UE within its radiocoverage. More specifically, each cell (often referred to as a servingcell) provides services to serve one or more UEs within its radiocoverage (e.g., each cell schedules the downlink and optionally uplinkresources to at least one UE within its radio coverage for downlink andoptionally uplink packet transmissions). The base station cancommunicate with one or more UEs in the radio communication systemthrough the plurality of cells. A cell may allocate sidelink (SL)resources for supporting Proximity Service (ProSe) or Vehicle toEverything (V2X) service. Each cell may have overlapped coverage areaswith other cells.

As discussed above, the frame structure for NR is to support flexibleconfigurations for accommodating various next generation (e.g., 5G)communication requirements, such as Enhanced Mobile Broadband (eMBB),Massive Machine Type Communication (mMTC), Ultra-Reliable andLow-Latency Communication (URLLC), while fulfilling high reliability,high data rate and low latency requirements. The OrthogonalFrequency-Division Multiplexing (OFDM) technology as agreed in 3rdGeneration Partnership Project (3GPP) may serve as a baseline for NRwaveform. The scalable OFDM numerology, such as the adaptive sub-carrierspacing, the channel bandwidth, and the Cyclic Prefix (CP) may also beused. Additionally, two coding schemes are considered for NR: (1)Low-Density Parity-Check (LDPC) code and (2) Polar Code. The codingscheme adaption may be configured based on the channel conditions and/orthe service applications.

Moreover, it is also considered that in a transmission time interval TXof a single NR frame, a downlink (DL) transmission data, a guard period,and an uplink (UL) transmission data should at least be included, wherethe respective portions of the DL transmission data, the guard period,the UL transmission data should also be configurable, for example, basedon the network dynamics of NR. In addition, sidelink resources may alsobe provided in an NR frame to support ProSe services or V2X services.

In addition, the terms “system” and “network” herein may be usedinterchangeably. The term “and/or” herein is only an associationrelationship for describing associated objects, and represents thatthree relationships may exist. For example, A and/or B may indicatethat: A exists alone, A and B exist at the same time, and B existsalone. In addition, the character “/” herein generally represents thatthe former and latter associated objects are in an “or” relationship.

In general, system information may be transmitted in a MasterInformation Block (MIB) and one or more System Information Blocks(SIBs). System information may include cell access information, radioresource configuration, synchronization signal, cell specificinformation, frequency specific information, system wide information,Public Warning System (PWS) information, etc.

In an LTE system, system information may be broadcast periodically.Based on well-defined information in the MIB and SIBs, a UE may receivethe system information necessary for accessing a cell. Once the UEpowers on and reads the MIB, the UE may synchronize to the cell.Furthermore, if the UE camps on the cell, the UE may read more systeminformation from the cell and perform an RRC connection setup procedureand data transmission. The system information may be broadcastrepeatedly by the base station (e.g., an LTE eNB or an LTE cell). Theperiodicities of the MIB and SIBs may be defined and not necessarily bethe same.

In the next generation (e.g., 5G NR) RAN, the distribution of systeminformation may become more flexible and different from that in an LTEnetwork. For example, the system information included in the MIB andSIBs may be different from that in the LTE system. The distribution ofsystem information may be broadcast periodically by a base station(e.g., an NR gNB or an NR cell) or requested on demand by the UE. Thebase station may broadcast or transmit via dedicated signaling (e.g.,via an RRC message) the system information requested by the UE. In someimplementations, the minimum system information, including the MIB andthe SIB1, may be broadcast periodically. The SIB1 may also be known asthe Remaining Minimum System Information (RMSI), while the remainingSIBs, either broadcast on demand or unicast on demand, may be referredto as the other system information (e.g., other SI).

In the next generation (e.g., 5G NR) RAN, the minimum system informationmay be structured to be as compact as possible. For example, the size ofSIB1 may be restricted to a Transport Block (TB) size of roughly 3000bits, considering the limitation of the Physical Downlink Shared Channel(PDSCH) carrying the RMSI. With more innovative features (e.g., beams,higher frequencies, Supplementary Uplink (SUL), network sharing with atmost 12 Public Land Mobile Networks (PLMNs), etc.) in the nextgeneration RAN, it is observed that the size of the SIB1 could increasesignificantly without proper restrictions. Thus, in some implementationsof the present disclosure, the system information content may bemodified in order to reduce the size of the SIB1.

In some implementations of the present disclosure, when a UE receives aSIB1 broadcast by a cell, the UE may store the SIB1, and apply theessential system information contained in the SIB1 to camp on, access,and/or connect to the cell. In some implementations of the presentdisclosure, the UE may apply cell-selection-related information in theSIB1 to determine whether a cell supports the PLMN selected by the UE.In some implementations, the UE may apply unified access-barring-relatedinformation to determine whether the UE is barred or accepted by a cell.If the UE is barred, its access attempt may fail. If the UE is accepted,its access attempt may succeed. In some implementations, the UE mayapply a common serving cell configuration to configure the setting for acell. In some implementations, the UE may apply a few of the UE timersand/or constants in the SIB1 for a cell. In some implementations, the UEmay apply system information scheduling-related information to requestother SIB(s) from a cell. As the next-generation RAN becomesincreasingly flexible and functional, more and more system parametersare required. However, since the SIB1 size is limited due to the TBsize, further consideration is needed on how to signal the requiredsystem information in the SIB1. Thus, some implementations of thepresent disclosure may provide a signaling mechanism for cell selectioninformation and/or UE timers and constants. In some implementations ofthe present disclosure, the mechanisms for SIB1 transmission/receptionare introduced.

In some implementations of the present disclosure, the SIB1 may betransmitted by a base station or cell on a transport channel (e.g., aDownlink Shared Channel (DL-SCH)). In some implementations, the SIB1content may be split, by the base station or cell, into at least twoTransport Blocks (TBs) to comply with Transport Block Size (TBS)restrictions.

FIG. 1 is a timing diagram illustrating a split of SIB1 content, inaccordance with example implementations of the present disclosure. Asillustrated in FIG. 1 , the SIB1 content is split into a number (e.g.,“B” being an integer) of SIB1 TBs 102_1 to 102_B, by the base station orcell, within a SIB1 transmission period 104.

In some implementations, the SIB1 TBs 102_1 to 102_B may only carry theSIB1 content. In some other implementations, the SIB1 TBs 102_1 to 102_Bmay carry the mixture of at least one of the SIB1 content, the controlinformation (e.g., Downlink Control Information (DCI), Medium AccessControl (MAC) Control Element (CE)) and the data. For example, one SIB1TB may carry the SIB1 content and the control information, and anotherSIB1 TB may carry the SIB1 content and the data. For example, only thelast SIB1 TB (e.g., the SIB1 TB 102_B) in the SIB1 transmission period(e.g., the SIB1 transmission period 104) or the SIB1 repetition period(e.g., a SIB1 repetition period 108) may carry the control informationor the data.

In some implementations of the present disclosure, the SIB1 TBs 102_1 to102_B may be consecutive in the time domain. In some otherimplementations, the SIB1 TBs 102_1 to 102_B may not be consecutive inthe time domain. In some implementations, if the SIB1 TBs 102_1 to 102_Bare not consecutive, the gap between two of the SIB1 TBs 102_1 to 102_B(e.g., the gap between two neighbor SIB1 TBs) may be pre-configured, orsignaled by at least one of following items: the previous SIB1 TB(s),the MIB, and the Control Resource Set (CORESET) of SIB1. In someimplementations, the MIB (or the SIB1 or the CORESET of SIB1) mayindicate the gap between two SIB1 TBs, and the gap between two SIB1 TBsmay be applied to at least the SIB1 TB(s) transmitted before the nextMIB. In some other implementations, the gap between two SIB1 TBs may beapplied to the SIB1 TBs within a SIB1 repetition period (e.g., the SIB1repetition period 108 shown in FIG. 1 ). In the SIB1 repetition period,the SIB1 content may not be changed and the SIB1 transmission may berepetitive within every SIB1 transmission period (e.g., the SIB1transmission period 104 shown in FIG. 1 ).

In some implementations of the present disclosure, one SIB1 TB maysignal the gap between itself and the upcoming SIB1 TB(s). These SIB1TBs may belong to the same transport channel (e.g., DL-SCH). Forexample, if the SIB1 content is split/distributed into B SIB1 TBs (e.g.,the SIB1 TBs 102_1 to 102_B shown in FIG. 1 ) by the base station orcell, the UE may monitor the B SIB1 TBs to receive all of the SIB1content.

In some implementations of the present disclosure, the cell may includeat least one bit in a SIB1 TB or in a MIB to indicate that the remainingSIB1 content will come in the following TB(s). In some otherimplementations, the cell may include at least one bit in a SIB1 TB toindicate that this SIB1 TB is the last one for carrying the entire SIB1content.

In some implementations of the present disclosure, where the SIB1 issplit into several SIB1 TBs, the SIB1 transmission period (e.g., theSIB1 transmission period 104 shown in FIG. 1 ) may be referred to as thetime duration from the beginning of the first SIB1 TB of these SIB1 TBsto the end of the last SIB1 TB of these SIB1 TBs. The repetition ofthese SIB1 TBs (e.g., the SIB1 TBs 102_1 to 102_B in the SIB1transmission period 104 shown in FIG. 1 ) may be made within the SIB1repetition period (e.g., the SIB1 repetition period 108 shown in FIG. 1). In some implementations, the length of the SIB1 repetition period maybe, but is not limited to, 160 ms.

In some implementations of the present disclosure, the UE may monitorand receive all SIB1 TBs (e.g., the SIB1 TBs 102_1 to 102_B) in the SIB1repetition period (e.g., the SIB1 repetition period 108). In some otherimplementations, the UE may monitor, receive, and decode the requiredSIB1 TBs to construct the complete SIB1 content. For example, if the UEhas successfully monitored, received, and decoded the first B SIB1 TBsin the SIB1 repetition period, the UE may skip monitoring (or receiving)the remaining SIB1 TBs in this SIB1 repetition period. In some otherimplementations, the UE may monitor the required SIB1 TBs to constructthe required content. For example, if the UE has successfully monitored,received, and decoded certain SIB1 TB(s) and constructed the requiredSIB1 content (e.g., the cell selection information) in the SIB1repetition period, the UE may skip monitoring (or receiving) theremaining SIB1 TB(s) in this SIB1 repetition period.

In some implementations of the present disclosure, the MIB may indicateat least one of the following parameters:

1) the value B (e.g., the number of SIB1 TBs in a SIB1 transmissionperiod),

2) the SIB1 repetition period, and

3) the SIB1 transmission period.

In some other implementations, the MIB may carry at least one of theabove-mentioned parameters (e.g., the value B, the SIB1 repetitionperiod, and the SIB1 transmission period).

In some other implementations, the MIB may indicate the resources (e.g.,CORESET, Physical Downlink Control Channel (PDCCH), or PDSCH) forcarrying at least one of the above-mentioned parameters (e.g., the valueB, the SIB1 repetition period, and the SIB1 transmission period).

In some other implementations, each SIB1 TB may indicate a SIB1transmission period. For example, each SIB1 TB may carry theindication(s) of at least one of the SIB1 transmission period, the valueB, and the SIB1 repetition period. For example, each SIB1 TB mayindicate the resources (e.g., CORESET or PDCCH) to carry theindication(s) of at least one of the SIB1 transmission period, the valueB, and the SIB1 repetition period.

In some other implementations, the first SIB1 TB (e.g., the SIB1 TB102_1 shown in FIG. 1 ) in the SIB1 transmission period may indicate atleast one of the SIB1 transmission period, the value B, and the SIB1repetition period. For example, the first SIB1 TB in a SIB1 transmissionperiod may carry the indication(s) of at least one of the SIB1transmission period, the value B, and the SIB1 repetition period. Forexample, the first SIB1 TB in a SIB1 transmission period may indicatethe resources (e.g., CORESET or PDCCH) to carry the indication(s) of atleast one of the SIB1 transmission period, the value B, and the SIB1repetition period.

In some other implementations, the first SIB1 TB in a SIB1 repetitionperiod may indicate at least one of the SIB1 transmission period, thevalue B, and the SIB1 repetition period. For example, the first SIB1 TBin a SIB1 repetition period may carry the indication(s) of at least oneof the SIB1 transmission period, the value B, and the SIB1 repetitionperiod. For example, the first SIB1 TB in a SIB1 repetition period mayindicate the resources (e.g., CORESET or PDCCH) to carry theindication(s) of at least one of the SIB1 transmission period, the valueB, and the SIB1 repetition period.

In some implementations of the present disclosure, all SIB1 TBs mayapply the same CORESET configuration which is indicated by the MIB.After receiving the CORESET configuration indicated by the MIB, the UEmay monitor the SIB1 TBs. The CORESET configuration indicated by the MIBmay provide the resource allocation of all B SIB1 TBs. In someimplementations, the #n SIB1 TB may indicate the CORESET for the #n+1SIB1 TB. After receiving the CORESET configuration indicated in the #nSIB1 TB, the UE may monitor the #n+1 SIB1 TB. The CORESET configurationindicated by the #n SIB1 TB may provide the resource allocation of the#n+1 SIB1 TB.

Cell Selection Information

In some implementations of the present disclosure, the SIB1 may includesystem information indicating the parameters for cell (re)selection. Insome implementations, such cell selection information may be carried inan Information Element (IE) (e.g., cellSelectionInfo IE). Upon receivingthe SIB1 from a cell, a UE which is operated in the RRC_IDLE,RRC_INACTIVE, or RRC_CONNECTED state may store the received SIB1. The UEmay read the cell selection information from the SIB1 broadcast by thebase station or cell, and determine whether to select the cell to campon/access based on certain rules and/or criteria (e.g., the cellselection criterion S).

In some implementations of the present disclosure, a UE may perform cellselection when the UE powers on or moves out of the cell coverage. TheUE may perform initial cell selection without prior knowledge of whichRadio Frequency (RF) channels are Radio Access Technology (RAT)frequencies (e.g., LTE frequencies, NR frequencies). The UE may performcell selection by leveraging stored information. Cell selection mayrefer to a process in which the UE may search for a suitable cell fromwhich the UE is able to receive communication services. In someimplementations, a cell may be deemed a suitable cell if this cell meetsone or more cell selection criteria (e.g., the cell selection criterionS). A cell may be deemed a suitable cell if this cell is part of eitherthe selected PLMN of the UE or the registered PLMN of the UE or PLMN ofthe Equivalent PLMN list of the UE, and a tracking area code (TAC) isprovided by the cell for that PLMN. If the suitable cell is found, theUE may camp on and/or access this cell. Additionally, in someimplementations, cell reselection may refer to a process which allowsthe UE to camp on the best cell or a better cell when the channelconditions change. For example, while the UE camps on a serving cell,the UE may regularly search for a better cell(s) according to the cellreselection criteria. If a better cell is found, the UE may (re)selectthe better cell as a new serving cell and camp on and/or access thiscell.

In some implementations of the present disclosure, if the cell selectioncriterion S is fulfilled, the selected cell may match the condition thatboth of the cell selection received (RX) level value (in decibels, ordB) (e.g., Srxlev) and the cell selection quality value (dB) (e.g.,Squal) are positive.

In some implementations, the cell selection RX level value (dB) (e.g.,Srxlev) may be equal to, but not limited to, “the measured cell RX levelvalue (e.g., the Reference Signal Received Power (RSRP), Q_(rxlevmeas))”minus “the minimum required RX level in the cell (dBm) (e.g.,Q_(rxlevmin))” minus “an offset to the signaled Q_(rxlevmin) taken intoaccount in the Srxlev evaluation as a result of a periodic search for ahigher priority PLMN while the UE camps on a cell normally in a VirtualPLMN (VPLMN) (e.g., Q_(rxlevminoffset))” minus “a power compensationvalue (e.g., P_(compensation))” minus “an offset temporarily applied toa cell (e.g., Qoffset_(temp))”, as shown in Equation (1) below.

On the other hand, the cell selection quality value (Squal) may be equalto, but not limited to, “the measured cell quality value (e.g.,Reference Signal Received Quality (RSRQ) or Q_(qualmeas))” minus “theminimum required quality level in the cell (dB) (e.g., Q_(qualmin))”minus “an offset to the signaled Q_(qualmin) taken into account in theSqual evaluation as a result of a periodic search for a higher priorityPLMN while the UE camps on a cell normally in a VPLMN (e.g.,Q_(qualminoffset))” minus “an offset temporarily applied to a cell(e.g., Qoffset_(temp))”, as shown in Equation (2) below.

In some implementations of the present disclosure, the parametersrequired to calculate the cell selection RX level value and the cellselection quality value (e.g., as shown in Table 1), may be eitherpreconfigured to the UE or broadcast by the base station or cell in SIB1to the UE. It is possible that some parameters are preconfigured to theUE, some parameters are determined based on the UE's implementation, andsome parameters are broadcast by the base station or cell in the SIB1 tothe UE. In some implementations, it is possible that the UE may storeand use some parameters broadcast or unicast from a different basestation or cell. For example, the signaled values Q_(rxlevminoffset) andQ_(qualminoffset) may be only applied when a cell is evaluated for cellselection as a result of a periodic search for a higher-priority PLMNwhile the UE camps on a cell normally in a VPLMN. During the periodicsearch for a higher-priority PLMN, the UE may check the cell selectioncriterion S of a cell using parameter values obtained from a differentcell of the higher-priority PLMN.

In some implementations, the detailed formula and parameters of the cellselection criterion S may be shown as follows and in Table 1.Srxlev=Q _(rxlevmeas)−(Q _(rxlevmin) +Q _(rxlevminoffset))−P_(compensation) −Qoffset_(temp)  Equation (1)Squal=Q _(qualmeas)−(Q _(qualmin) +Q_(qualminoffset))−Qoffset_(temp)  Equation (2)

where:

Parameters in Cell Selection Criterion S Srxlev Cell selection RX levelvalue (dB) Squal Cell selection quality value (dB) Qoffset_(temp) Offsettemporarily applied to a cell (dB) Q_(rxlevmeas) Measured cell RX levelvalue (e.g., RSRP) Q_(qualmeas) Measured cell quality value (e.g., RSRQ)Q_(rxlevmin) Minimum required RX level in the cell (dBm). If the UEsupports SUL frequency for this cell, Q_(rxlevmin) may be obtained fromq-RxLevMin-sul, if present, in SIB1, else Q_(rxlevmin) is obtained fromq-RxLevMin in SIB1 Q_(qualmin) Minimum required quality level in thecell (dB) Q_(rxlevminoffset) Offset to the signaled Q_(rxlevmin) takeninto account in the Srxlev evaluation as a result of a periodic searchfor a higher priority PLMN while the UE camps on a cell normally in aVPLMN Q_(qualminoffset) Offset to the signaled Qqualmin taken intoaccount in the Squal evaluation as a result of a periodic search for ahigher priority PLMN while the UE camps on a cell normally in a VPLMNP_(compensation) If the UE supports the additionalPmax in theNS-PmaxList, if present, in SIB1: max(P_(EMAX1) − P_(PowerClass), 0) −(min(P_(EMAX2), P_(PowerClass)) − min(P_(EMAX1), P_(PowerClass))) (dB);else: max(P_(EMAX1) − P_(PowerClass), 0) (dB)

In Table 1, the NS-PmaxList may include a list of additional Pmax valuesand additional spectrum emission values, where the Pmax values may beused to limit the UE's UL transmission power on a carrier frequency. TheP_(PowerClass) may be the maximum UE output power for the transmissionbandwidth, where the P_(PowerClass) may or may not consider anytolerance. The P_(EMAX1) and the P_(EMAX2) may be power values. In someimplementations, the NS-PmaxList, the P_(PowerClass), the P_(EMAX1), andthe P_(EMAX2) may be signaled by the SIB1, other system information(e.g., including SIB(s) other than the SIB1), or RRC signaling.

It should be noted that the cell selection criterion (e.g., the cellselection criterion S) described herein is only for illustrativepurposes, and not intended to limit the scope of the present invention.The description of the cell selection criterion may suggest manyvariations and alternatives. For example, one or more parameters may beintroduced in/removed from the formula of the Srxlev and/or the Squalshown above, as long as the cell selection criterion can be directly orindirectly derived from the minimum required RX level (e.g., theQ_(rxlevmin)).

In some implementations of the present disclosure, the UE may receive aminimum required received level factor (e.g., the q-RxLevMin) via systeminformation transmitted by the base station or the cell. In some suchimplementations, the q-RxLevMin-sul may be in the form of an offset tothe minimum required received level factor (e.g., the q-RxLevMin). Suchan offset may be presented in the SIB3 and/or the SIB4 transmitted bythe base station or the cell. The UE may obtain a minimum requiredreceived level (e.g., the Q_(rxlevmin)) based on the minimum requiredreceived level factor (e.g., the q-RxLevMin) and the offset multipliedby Y (e.g., Y×q-RxLevMin-sul), where Y is an integer. In some suchimplementations, Y may be an integer larger than one. The UE may thendetermine the cell selection criterion S based on the Q_(rxlevmin), andperform cell reselection based on the cell selection criterion S.

In some other implementations of the present disclosure, theq-RxLevMin-sul may be in the form of an absolute value. In some suchimplementations, the UE may obtain the minimum required received level(e.g., the Q_(rxlevmin)) based on either the q-RxLevMin-sul (e.g., inthe form of an absolute value) or the q-RxLevMin.

It should be noted that the q-RxLevMin-sul described herein may be inthe form of an offset or in the form of an absolute value unlessotherwise indicated.

In some other implementations, if the UE supports an SUL frequency for acell and/or if the q-RxLevMin-sul is broadcast in the SIB1 by the basestation or cell, the UE may calculate the Q_(rxlevmin) obtained from theq-RxLevMin-sul broadcast by the base station or cell.

In some other implementations, if the UE supports an SUL frequency for acell and if the q-RxLevMin-sul is not broadcast in SIB1 by the basestation or cell, the UE may calculate the Q_(rxlevmin) obtained from astored q-RxLevMin-sul. The stored q-RxLevMin-sul may be acquired fromother base stations or cells. For example, the stored q-RxLevMin-sul maybe acquired from another cell which the UE selected or camped on before.For example, the stored q-RxLevMin-sul may be acquired from neighboringcell(s). In some implementations, the neighboring cells may be the cellsfor which the UE has a positive cell selection RX level value and apositive cell selection quality value. In some implementations, the UEmay adopt the q-RxLevMin-sul from one cell satisfying the cell selectioncriterion S when the UE evaluates the cell selection criterion S ofanother cell which may not broadcast/transmit the q-RxLevMin-sul in theSIB1. In some implementations, the q-RxLevMin-sul may be broadcast orunicast by the neighboring cells.

In some implementations of the present disclosure, if the UE stores morethan one q-RxLevMin-sul value, it may be up to the UE's implementationto select one of the stored q-RxLevMin-sul values as the q-RxLevMin-sulto calculate the Q_(rxlevmin). In some other implementations, if the UEhas more than one stored q-RxLevMin-sul values, the UE may use thelowest or the highest q-RxLevMin-sul value among the storedq-RxLevMin-sul values as the q-RxLevMin-sul to calculate theQ_(rxlevmin). In some other implementations, if the UE acquires orstores more than one q-RxLevMin-sul value, the UE may use the average ofthe acquired or stored q-RxLevMin-sul values as the q-RxLevMin-sul tocalculate the Q_(rxlevmin). It should be noted that in some aspects,when the UE evaluates the cell selection criterion S for a cell (whichmay not broadcast the q-RxLevMin-sul and the q-RxLevMin), themechanism(s) of how the UE applies the q-RxLevMin-sul (e.g., based onacquired q-RxLevMin-sul values, based on stored q-RxLevMin-sul values,based on the q-RxLevMin-sul from neighboring cell(s)) may also beapplied in the cell selection criterion evaluation process.

In some implementations of the present disclosure, if the UE does notstore the q-RxLevMin-sul value(s) and may not acquire the q-RxLevMin-sulvalue(s) from any cell (e.g., serving cells, camped cells, neighboringcells), the UE may use a default q-RxLevMin-sul value. In someimplementations, the default q-RxLevMin-sul value may be preconfiguredor predefined. In some implementations, the default q-RxLevMin-sul valuemay be the q-RxLevMin value for a normal UL carrier. The q-RxLevMinvalue may be a minimum required RX level in the cell (dBm) on a normalUL carrier. In some implementations, compared to the SUL carrier, thecoverage of a normal UL carrier may be smaller. In some implementations,compared to the SUL carrier, the frequency of a normal UL carrier ishigher than that of the SUL carrier.

In some implementations of the present disclosure, if the UE supports anSUL frequency for a cell and/or if the q-RxLevMin-sul is not broadcastin the SIB1 by this cell, the UE may calculate the first Q_(rxlevmin)according to the q-RxLevMin for the normal UL carrier, determine a firstcell selection criterion S based on the first Q_(rxlevmin), and performcell selection based on the first cell selection criterion S.

Once the UE selects such a cell during the cell selection, the UE mayfurther send an RRC message (e.g., an RRC system information requestmessage) to the cell and ask for the q-RxLevMin-sul. The q-RxLevMin-sulmay be cell-specific. The UE may use the q-RxLevMin-sul value forintra-frequency cell reselection, inter-frequency cell reselection, andinter-RAT cell reselection. In some implementations, an intra-frequencycell reselection procedure may refer to a process in which the UE mayselect another cell on the same frequency as that of the serving cell.In some implementations, an inter-frequency cell reselection proceduremay refer to a process in which the UE may select another cell on afrequency different from the frequency of the serving cell. In someimplementations, an inter-RAT frequency procedure may refer to a processin which the UE may perform cell reselection to a neighboring cell thatbelongs to a RAT different from the serving cell. A cell in an inter-RATfrequency may be referred to as an inter-RAT cell.

Once the UE acquires the q-RxLevMin-sul, the UE may calculate a secondQ_(rxlevmin) according to the q-RxLevMin-sul, determine a second cellselection criterion S based on the second Q_(rxlevmin), and perform cell(re)selection (e.g., intra-frequency cell reselection, inter-frequencycell reselection, or inter-RAT cell reselection) based on the secondcell selection criterion S.

In some implementations of the present disclosure, the base station (orthe cell) may transmit the q-RxLevMin to the UE in the SIB1, and furthertransmit an SUL-related factor (e.g., the q-RxLevMin-sul in the form ofan absolute value) in other system information in response to receivingthe RRC system information request message from the UE.

The reason that a cell does not include the q-RxLevMin-sul in the SIB1may be to reduce the SIB1 size, though the cell supports the SUL.However, if the UE requests the q-RxLevMin-sul from a cell via an RRCmessage (e.g., an RRC system information request message) andsuccessfully acquires the q-RxLevMin-sul from the cell, the UE may usethe SUL of the cell when the cell selection criterion S is fulfilled byconsidering the q-RxLevMin-sul. In some implementations, if the cellprovides the q-RxLevMin-sul in other system information (e.g., includingSIB(s) other than the SIB1) or an RRC message (e.g., RRC reconfigurationmessage), it means that the cell may ask the UE to switch to the SULcarrier. For example, upon receiving the q-RxLevMin-sul via other systeminformation or via an RRC message, the UE may switch to the SUL carrierof the cell. In another example, upon receiving the q-RxLevMin-sul viaother system information or via an RRC message, the UE may perform cellselection criterion S evaluation for the SUL carrier. If the cellselection criterion S is fulfilled, the UE may switch to the SULcarrier. The reason may be for the purpose of normal UL carrieroffloading. In some other implementations, if the cell does notbroadcast the q-RxLevMin in the SIB1, the UE may request the q-RxLevMinfrom the base station or the cell via an RRC message (e.g., an RRCsystem information request message).

If the UE successfully acquires the q-RxLevMin from the cell, and thecell selection criterion S by calculating the q-RxLevMin value isfulfilled, the UE may switch to a normal UL carrier. In some otherimplementations, if the cell provides the q-RxLevMin in other systeminformation (e.g., including SIB(s) other than the SIB1) or an RRCmessage (e.g., RRC reconfiguration message), it means that the cell asksthe UE to switch to a normal UL carrier. If the q-RxLevMin matches thecell selection criterion S, the UE may switch to the normal UL carrier.For example, upon receiving the q-RxLevMin via other system informationor via an RRC message, the UE may switch to the normal UL carrier of thecell. In another example, upon receiving the q-RxLevMin via other systeminformation or via an RRC message, the UE may perform cell selectioncriterion S evaluation for the normal UL carrier. If the cell selectioncriterion S is fulfilled, the UE may switch to the normal UL carrier.

The field to indicate the q-RxLevMin in the SIB1 may require severalbits. The number of the bits may depend on the possible range of theq-RxLevMin value. For example, the q-RxLevMin value may be an integerwith a value ranging from −70 to −22 decibel-milliwatts (dBm). In someimplementations, it is possible that the q-RxLevMin-sul value may fallin the same range as the q-RxLevMin value. In some implementations, toreduce the SIB1 size, the q-RxLevMin-sul value may be further reduced.In some implementations, if the q-RxLevMin and the q-RxLevMin-sul havethe same value, the cell may broadcast the q-RxLevMin (or theq-RxLevMin-sul) and a specific indicator (e.g., a one-bit indicator) toindicate that the q-RxLevMin and the q-RxLevMin-sul have the same value.For example, if the specific indicator is set to “TRUE” or present inthe SIB1, the UE may know that the values of the q-RxLevMin and theq-RxLevMin-sul are the same, and the UE may not further request theq-RxLevMin or the q-RxLevMin-sul from a cell/base station.

In some implementations of the present disclosure, the value ofq-RxLevMin-sul may be in the form of an offset to the q-RxLevMin value.For example, the expression “q-RxLevMin minus q-RxLevMin-sul” (in dBm)may represent the minimum required RX level for SUL in the cell. Forexample, the expression “q-RxLevMin minus q-RxLevMin-sul” (in dBm) mayrepresent the minimum required RX level for the normal UL carrier in thecell. In some implementations, the value of q-RxLevMin-sul may be 0, 1,2, . . . , X, where X may decide the bit number of the q-RxLevMin-sul.In some other implementations, the value of q-RxLevMin-sul may be 0, −1,−2, . . . , −X, and the expression “q-RxLevMin plus q-RxLevMin-sul” (indBm) may represent the minimum required RX level for SUL in the cell. Insome other implementations, the value of q-RxLevMin-sul may be 0, −1,−2, . . . , −X, and the expression “q-RxLevMin plus q-RxLevMin-sul” (indBm) may represent the minimum required RX level for the normal ULcarrier in the cell.

In some implementations of the present disclosure, to further reduce theSIB1 size, the expression “q-RxLevMin minus/plus “Y timesq-RxLevMin-sul”” (in dBm) may represent the minimum required RX levelfor SUL in the cell, where Y may be predefined or broadcast in the SIB1.In some implementations, Y may be an integer. In some implementations, Ymay be an integer larger than one. In some implementations, theexpression “q-RxLevMin minus/plus “Y times q-RxLevMin-sul” (in dBm) mayrepresent the minimum required RX level for the normal UL carrier in thecell.

In some implementations of the present disclosure, if the q-RxLevMin-sulis not present in the system information (e.g., SIB1, SIB2, SIB3, SIB4,SIB5), the UE may consider that the q-RxLevMin-sul and the q-RxLevMinmay have the same value, and the UE may obtain the Q_(rxlevmin) based onthe q-RxLevMin value for SUL. In some other implementations, if theq-RxLevMin-sul is not present in the system information (e.g., SIB1,SIB2, SIB3, SIB4, SIB5), the UE may consider the SUL as being notsupported, and the UE may obtain the Q_(rxlevmin) based on theq-RxLevMin for the normal UL carrier. In some other implementations, ifthe q-RxLevMin-sul is not present in the system information (e.g., SIB1,SIB2, SIB3, SIB4, SIB5), the UE may consider the q-RxLevMin-sul valuebeing different from the q-RxLevMin value, and the UE may request theq-RxLevMin-sul from a cell or a base station, or read the q-RxLevMin-sulin other system information (e.g., SIB2, SIB3, SIB4, SIB5) or an RRCmessage (e.g., RRC reconfiguration message).

In some implementations of the present disclosure, the base station orcell may transmit a minimum required received level factor (e.g., theq-RxLevMin) and an offset (e.g., the q-RxLevMin-sul in the form of anoffset) via system information, where the offset may be transmitted inresponse to an RRC system information request message received by thebase station from a UE. For example, the UE may request theq-RxLevMin-sul from a cell or a base station by sending an RRC message(e.g., RRC system information request message) or by sending a preambleassociated with the request for the q-RxLevMin-sul.

In some implementations of the present disclosure, the parameters (e.g.,X, Y, or q-RxLevMin-sul), which the UE may use to determine the minimumrequired RX level for an SUL carrier or for a normal UL carrier in thecell, may be transmitted by a cell (e.g., camped cell, serving cell) ora base station in other system information (e.g., SIB2, SIB3, SIB4,SIB5) or an RRC message (e.g., RRC reconfiguration message). In someimplementations, the UE may acquire the parameters (e.g., X, Y, orq-RxLevMin-sul), which the UE may use to determine the minimum requiredRX level for an SUL carrier or for a normal UL carrier in the cell, fromcertain cell(s) (e.g., the neighboring cells).

In some implementations of the present disclosure, the specificindicator and/or the q-RxLevMin-sul may not be limited to be applied inthe SIB1. For example, the specific indicator and/or the q-RxLevMin-sulmay be applied to the parameters/information in other system informationto reduce the size of SIBs. In some implementations, the SIBS may betransmitted by the cell or the base station via periodic broadcast,one-shot broadcast, or dedicated signaling, to UE(s). In someimplementations, the UE may request the SIBS on demand. In someimplementations, the q-RxLevMin-sul may be transmitted by the cell orbase station in the intra-frequency cell reselection information (e.g.,the intraFreqCellReselectionInfo IE in the System Information Block 2(SIB2)) to the UE(s). In some implementations, the q-RxLevMin-sul may betransmitted by the cell or base station in the neighboring cell relatedinformation for intra-frequency cell reselection (e.g., theintraFreNeighCellInfo IE in the System Information Block 3 (SIB3)) tothe UE(s). In some implementations, the q-RxLevMin-sul may betransmitted by the cell or base station in the inter-frequency cellreselection information (e.g., the interFreqCarrierFreqInfo IE in theSystem Information Block 4 (SIB4)) to the UE(s). In someimplementations, the q-RxLevMin-sul may be transmitted by the cell orbase station in the neighboring cell related information forinter-frequency cell reselection (e.g., the interFreNeighCellInfo IE inthe SIB4) to the UE(s). In some implementations, the q-RxLevMin-sul maybe transmitted by the cell or base station in the inter-RAT cellreselection information (e.g., the CarrierFreRAT IE in the SystemInformation Block 5 (SIB5)) to the UE(s). For example, the RAT may beE-UTRA. In some implementations, the q-RxLevMin-sul may be transmittedby the cell or base station in the inter-RAT neighboring cell relatedinformation for cell reselection (e.g., the RAT-FreqNeighCellInfo IE inthe SIBS) to the UE(s). For example, the RAT may be E-UTRA.

In some implementations, the RAT (e.g., E-UTRA) may support the SULcarrier. If the UE acquires (or receives) the q-RxLevMin-sul in othersystem information (e.g., SIB2, SIB3, SIB4, and SIBS) from a cell orbase station, the UE may adopt the value of the acquired q-RxLevMin-sulfor intra-frequency cell (re)selection, intra-frequency cell reselectionfor neighboring cells, inter-frequency cell (re)selection,inter-frequency cell reselection for neighboring cells, inter-RAT cellreselection, or inter-RAT neighboring cell reselection. For example, aUE camping on an E-UTRA cell may perform inter-RAT neighboring cellreselection or inter-RAT cell (re)selection to an NR cell, based on theq-RxLevMin-sul received from an E-UTRA cell. For example, a UE campingon an NR cell may perform inter-RAT neighboring cell reselection orinter-RAT cell (re)selection to an E-UTRA cell, based on theq-RxLevMin-sul received from an NR cell.

FIG. 2 is a signaling flow diagram illustrating a signaling flow betweena UE and a cell, in accordance with example implementations of thepresent disclosure. As shown in FIG. 2 , in action 202, a UE 21 maytransmit an RRC system information request message (e.g.,RRCSystemInfoRequest message) to a cell 23 (or a base station) torequest the q-RxLevMin-sul.

In action 204, the UE 21 may receive the q-RxLevMin-sul from the cell23. In action 206, the UE 21 may perform cell (re)selection (e.g.,intra-frequency cell (re)selection, intra-frequency cell reselection forneighboring cells, inter-frequency cell (re)selection, inter-frequencycell reselection for neighboring cells, inter-RAT cell reselection, orinter-RAT neighboring cell reselection) using the q-RxLevMin-sul valuereceived in action 204.

In some implementations of the present disclosure, the combinations ofparameter values used for cell (re)selection information (e.g.,parameters in Table 1) may be defined. Taking the q-RxLevMin-sul and theq-RxLevMin as an example, the combinations of different values of theq-RxLevMin-sul and the q-RxLevMin are shown in Table 2. In Table 2, eachcombination of the q-RxLevMin-sul and the q-RxLevMin is indexed, and thecell may transmit the index of the candidate combination(s) to the UEvia the SIB1, other system information, or RRC messages using theindexed approach.

It should be noted that the combinations of the q-RxLevMin-sul and theq-RxLevMin shown in Table 2 are for illustrative purposes only, and notintended to limit the scope of the present disclosure. In someimplementations, the defined combinations may be the frequently usedsetting by the cell and UE. In some implementations, the definedcombinations may be the more reasonable combination from the systempoint of view. Such combinations may be pre-configured or defined in the3GPP specification. In some other implementations, deriving theparameter/information/criterion for cell (re)selection may not belimited to the combinations of the q-RxLevMin-sul and the q-RxLevMin.

TABLE 2 Examples of combinations of cell selection related parametersIndex q-RxLevMin q-RxLevMin-sul 000 −58 dBm −70 dBm 001 −58 dBm −64 dBm010 −46 dBm −70 dBm 011 −46 dBm −64 dBm 100 −34 dBm −70 dBm 101 −34 dBm−64 dBm 110 −22 dBm −70 dBm 111 −22 dBm −64 dBm

UE Timers and Constants

In some implementations of the present disclosure, the cell may informthe UE of the UE timers and constants for operation and maintenance.However, depending on the usage of the UE timers and constants, in somecases (e.g., considering the SIB1 size restriction), it may not be sourgent and necessary to broadcast all of the UE timers and constants inthe SIB1. Thus, in some implementations of the present disclosure, someUE timers and constants may not be present in the SIB1. In someimplementations, the UE timers and constants which are not present inthe SIB1 may be carried by other system information (e.g., SIB2, SIB3, .. . , and so on). In some implementations, the cell may inform the UE ofthe UE timers and constants which are not present in the SIB1 via RRCmessages (e.g., during an RRC setup procedure and/or an RRC resumeprocedure).

In some implementations of the present disclosure, the UE timers andconstants may include at least one of (but is not limited to) a firsttimer, a second timer, a third timer, a fourth timer, a first counter(or constant), and a second counter (or constant).

In some implementations of the present disclosure, the first timer maybe or may be similar to the T300 timer in LTE or NR, but it is notedthat the first timer is not necessarily limited to the T300 timer. Forexample, the UE may start the first timer when the UE transmits an RRCsetup request message. In some implementations, the UE may stop thefirst timer when the UE receives an RRC setup message or an RRC rejectmessage from the cell. In some implementations, the UE may stop thefirst timer when the UE performs cell reselection. In someimplementations, the UE may stop the first timer when the UE aborts anRRC connection establishment procedure requested by the upper layer(e.g., the Non-Access Stratum (NAS) layer). In some implementations,when the first timer expires, the UE may perform cell reselection.

In some implementations of the present disclosure, the second timer maybe or may be similar to the T301 timer in LTE or NR, but it is notedthat the second timer is not necessarily limited to the T301 timer. Forexample, the UE may start the second timer when the UE transmits an RRCreestablishment request message. In some implementations, the UE maystop the second timer when the UE receives an RRC reestablishmentmessage or an RRC setup message. In some implementations, the UE maystop the second timer when the UE observes that the selected cellbecomes unsuitable. Upon the second timer expiry, the UE may transitionto the RRC_IDLE state.

In some implementations of the present disclosure, the first counter (orconstant) may be or may be similar to the N310 counter (or constant) inLTE or NR, but it is noted that the first counter (or constant) is notnecessarily limited to the N310 counter (or constant). For example, theUE may maintain the first constant, which is the maximum number ofconsecutive “out-of-sync” indications for the Primary Cell (PCell) orthe Primary Secondary Cell (PSCell) received from the lower layer. Insome implementations, it is possible that one first constant exists forthe PCell and other first constant(s) exist for the PSCell(s). In someimplementations, it is possible that the PCell and the PSCell(s) mayapply the same first constant.

In some implementations of the present disclosure, the second counter(or constant) may be or may be similar to the N311 counter (or constant)in LTE or NR, but it is noted that the second counter (or constant) isnot necessarily limited to the N311 counter (or constant). For example,the UE may maintain the second constant, which is the maximum number ofconsecutive “in-sync” indications for the PCell or the PSCell receivedfrom the lower layer. In some implementations, it is possible that onesecond constant exists for the PCell and other second constant(s) existfor the PSCell(s). In some implementations, it is possible that thePCell and the PSCell(s) may apply the same second constant.

In some implementations, the third timer may be or may be similar to theT310 timer in LTE or NR, but it is noted that the third timer is notnecessarily limited to the T310 timer. For example, the UE may start thethird timer when the UE detects physical layer problems for the SpecialCell (SpCell) (e.g., the UE receives first consecutive out-of-syncindications from the lower layers). In some implementations, the UE maystop the third timer when the UE receives second consecutive in-syncindications from the lower layers for the SpCell. In someimplementations, the UE may stop the third timer when the UE receives anRRC reconfiguration message with a reconfigurationWithSync IE for thatcell group. In some implementations, the UE may stop the third timerwhen the UE initiates the RRC connection reestablishment procedure. Insome implementations, the UE may stop the third timer when the UEreleases the Secondary Cell Group (SCG) if the third timer is kept inthe SCG. In some implementations, if the third timer is kept in theMaster Cell Group (MCG) and the security is not yet activated, the UEmay transition to the RRC_IDLE state when the third timer expires. Insome implementations, if the third timer is kept in the MCG and thesecurity is activated, the UE may initiate an RRC connectionreestablishment procedure upon the third timer expiry. In someimplementations, if the third timer is kept in the SCG, the UE mayinform E-UTRAN or NR network about the SCG radio link failure byinitiating an SCG failure information procedure upon the third timerexpiry. It should be noted that the PCell may refer to the primary cellof an MCG, and the PSCell may refer to the primary cell of an SCG. Forthe dual connectivity case, the UE may be associated with one MCG andone SCG. For the multi-connectivity case, the UE may be associated withone MCG and several SCGs.

In some implementations of the present disclosure, the fourth timer maybe or may be similar to the T311 timer in LTE or NR, but it is notedthat the fourth timer is not necessarily limited to the T311 timer. Forexample, the UE may start the fourth timer when the UE initiates an RRCconnection re-establishment procedure. In some implementations, the UEmay stop the fourth timer when the UE selects a suitable NR cell or acell using another RAT. Upon the fourth timer expiry, the UE maytransition to the RRC_IDLE state.

In some implementations of the present disclosure, the second timer orthe fourth timer may not be included in the SIB1. In someimplementations, the second timer or the fourth timer may be carried inRRC messages (e.g., the 4^(th) Message (Msg4), the RRC setup message,the RRC reconfiguration message, the RRC resume message, the RRCreestablishment message, the RRC reject message, the RRC release messagewithout suspend configuration, or the RRC release message with suspendconfiguration), as shown in FIG. 3 .

FIG. 3 is a signaling flow diagram illustrating a signaling flow betweena UE and a cell, in accordance with example implementations of thepresent disclosure. As shown in FIG. 3 , in action 304, a UE 31 maytransmit an RRC message (e.g., the 3^(rd) Message (Msg3), the RRC resumerequest message, the RRC reestablishment request message, the RRC setuprequest message, the 5^(th) Message (Msg5), the RRC setup completemessage, the RRC resume complete message, or the RRC reestablishmentcomplete message) to a cell 33 if the cell 33 does not broadcast the UEtimers or constants in action 302.

In action 306, the cell 33 may reply to the UE 31 with an RRC message(e.g., the Msg4, the RRC setup message, the RRC reconfiguration message,the RRC resume message, the RRC reestablishment message, the RRC rejectmessage, the RRC release message without suspend configuration, or theRRC release message with suspend configuration) containing the UE timersand/or constants (e.g., the second timer and/or the fourth timer). Thenin action 308, the UE 31 may adopt the UE timers and/or constants fromthe cell 33.

According to FIG. 3 , the cell 33 may transmit a UE-specific secondtimer or a fourth timer to the UE 31. In some implementations, thesecond timer or the fourth timer may be carried in other systeminformation. In some implementations, the UE 31 may request the othersystem information via a 1^(st) Message (Msg1)-based system informationrequest procedure or a 3^(rd) Message (Msg3)-based system informationrequest procedure to acquire the second timer or the fourth timer. Theother system information may be delivered via broadcast or unicast. Itshould be noted that the signaling flow shown in FIG. 3 is not limitedto delivering the second timer and the fourth timer by the cell. In someother implementations, if the UE does not receive the timers and/orconstants from the cell, the UE may apply default value(s) to the UEtimers and/or constants. In some implementations, the default value(s)may be predefined or preconfigured by the network.

In some implementations of the present disclosure, when the Msg1-basedsystem information request procedure is applied, the Random Access (RA)preamble that the UE transmits (e.g., during Msg1 transmission in the4-step RA procedure, or during MsgA transmission in the 2-step RAprocedure) may correspond to the system information (e.g., SIB, SImessage) requested by the UE. In some implementations, the PhysicalRandom Access Channel (PRACH) occasion(s) where the UE transmits the RApreamble (e.g., during Msg1 transmission in the 4-step RA procedure, orduring MsgA transmission in the 2-step RA procedure) may be associatedwith the system information (e.g., SIB, SI message) requested by the UE.The UE may implicitly inform the base station of the requested systeminformation (e.g., SIB, SI message) via the RA preamble and/or the PRACHoccasion(s).

In some implementations of the present disclosure, when the Msg3-basedsystem information request procedure is applied, the Msg3 transmitted bythe UE may indicate the requested system information. The UE maydetermine whether the Msg3-based system information request procedure issuccessful or not based on a reception of the Msg4. In the Msg3-basedsystem information request procedure, the preamble(s) and/or the PRACHoccasions may not be reserved in some aspects of the presentimplementations. The RRC signaling may be used for the systeminformation request (e.g., the SI request) in the Msg3-based systeminformation request procedure. The RRC message including the SI requestmay be called an RRC system information request message (e.g.,RRCSystemInfoRequest message). The RRC message including the SI requestmay be carried by Signaling Radio Bearer 0 (e.g., SRB0) from an RRClayer of the UE to a MAC layer of the UE. The SRB0 carrying the RRCmessage including the SI request may be carried via the Common ControlChannel (CCCH), which may be configured with the Transparent Mode (TM)Radio Link Control (RLC) entity. For example, the Msg3 may include theCCCH Service Data Unit (SDU), which may include an RRC message for theSI request (e.g., the RRCSystemInfoRequest message).

In some implementations of the present disclosure, the UE timers andconstants, including at least one of (but not limited to) the firsttimer, the second timer, the third timer, the first counter (orconstant), the fourth timer, and the second counter (or constant), maybe defined to have candidate combinations of values. In someimplementations, the candidate combinations may be the frequently usedsetting by the cell and the UE. In some implementations, the candidatecombinations may be the most reasonable combination from the systempoint of view. Such combinations may be defined in the 3GPPspecification, or pre-configured by the network. In someimplementations, such combinations may be indexed, as shown in (but notlimited to) Table 3. The cell may transmit the index of the candidatecombination(s) to the UE via the SIB1, other system information, or RRCmessages using the indexed approach. n1 corresponds to 1, n2 correspondsto 2, and so on.

TABLE 3 Examples of Index-based indication of UE timers and constantsFourth Second Index Second Timer Timer First Constant Constant 000 100ms 1000 ms n1 n5 001 100 ms 1000 ms n1 n10 010 100 ms 1000 ms n2 n5 011100 ms 1000 ms n2 n10 100 200 ms 1000 ms n10 n5 101 200 ms 1000 ms n10n10 110 200 ms 1000 ms n20 n5 111 200 ms 1000 ms n20 n10

In some implementations of the present disclosure, a SIB (e.g., the SIB1or the MIB) may include a flag bit. If the flag bit in the SIB is set toa first value (e.g., “1”), the UE may treat this cell as a camp-ablecell. In some implementations, if the flag bit in the SIB is set to thefirst value, the UE may make an on-demand request for the correspondingSIB. In some implementations (e.g., the UE may send a preamblecorresponding to the requested SIB, the UE may send an RRC message(e.g., RRC system information request message) including the systeminformation request for the SIB), if the flag bit in the SIB is set tothe first value, the UE may treat the information in the SIB asincomplete information and make an on-demand request for thecorresponding SIB. In some implementations, if the cell receives theUE's request, the cell may reply to the UE with the SIB. In someimplementations, if the cell receives the UE's request, the cell maysend complete information in the SIB.

In some implementations of the present disclosure, the UE may make anon-demand request for the corresponding SIB after the UE completes theRRC connection establishment procedure. In some implementations, the UEmay apply default value(s) to the absent correspondinginformation/configuration, which the UE may receive with absentvalue(s). The default value may be preconfigured or predefined.

In some implementations of the present disclosure, if the flag bit inthe SIB1 is set to the first value, the UE may treat this cell as acamp-able cell and apply the default value(s) to the absentinformation/configuration. Once the UE completes the RRC connectionestablishment procedure, the UE may further on-demand request the SIBs.

In some implementations of the present disclosure, if the flag bit inthe SIB is set to a second value (e.g., “0”) or is absent in the SIB, itmeans that the UE cannot on-demand request the SIB. In someimplementations, if the flag bit in the SIB is set to a second value(e.g., “0”) or is absent in the SIB, the UE may treat this cell as abarred cell and perform cell (re)selection. In some implementations, ifat least one information field is not present in the corresponding SIB,and/or if the flag bit in the SIB is set to the second value or isabsent in the SIB, the UE may consider this cell as not providing thefunctions supported by the absent information field, and the UE maytreat this cell as a barred cell and perform cell selection.

FIG. 4 is a flowchart for a method of receiving system information, inaccordance with example implementations of the present disclosure. Asshown in FIG. 4 , the flowchart includes actions 402, 404, 406, 408 and410.

In action 402, a UE may receive a minimum required received level factor(e.g., the q-RxLevMin value) in a SIB1 from a base station.

In action 404, the UE may determine whether a first SUL-related factor(e.g., a q-RxLevMin-sul value defined in the SIB1 format) is present inthe SIB1.

In action 406, the UE may obtain a first minimum required received level(e.g., the Q_(rxlevmin)) based on the minimum required received levelfactor, when the first SUL-related factor is not present in the SIB1.

In action 408, the UE may determine a first cell selection criterion(e.g., the cell selection criterion S) based on the first minimumrequired received level.

In action 410, the UE may perform cell selection based on the first cellselection criterion.

In some implementations of the present disclosure, if the firstSUL-related factor is not present in the SIB1, the UE may performintra-frequency cell reselection when the UE receives a secondSUL-related factor (e.g., a q-RxLevMin-sul value defined in the SIB2format) in intra-frequency cell reselection information in a SIB2. Forexample, the UE may obtain a second minimum required received level(e.g., another Q_(rxlevmin)) based on the second SUL-related factor, anddetermine a second cell selection criterion (e.g., another cellselection criterion S) based on the second minimum required receivedlevel. Then, the UE may perform the intra-frequency cell reselectionbased on the second cell selection criterion.

In some other implementations of the present disclosure, if the firstSUL-related factor is not present in the SIB1, the UE may performinter-frequency cell reselection when the UE receives a secondSUL-related factor (e.g., a q-RxLevMin-sul value defined in the SIB4format) in inter-frequency cell reselection information in a SIB4. Forexample, the UE may obtain a second minimum required received level(e.g., another Q_(rxlevmin)) based on the second SUL-related factor, anddetermine a second cell selection criterion (e.g., another cellselection criterion S) based on the second minimum required receivedlevel. And the UE may perform the inter-frequency cell reselection basedon the second cell selection criterion.

In some implementations of the present disclosure, the first SUL-relatedfactor (and/or the second SUL-related factor) and the minimum requiredreceived level factor may fall in the same value range. For example, thevalues of all of the first SUL-related factor, the second SUL-relatedfactor, and the minimum required received level factor may, but notlimited to, be selected from the same integer range from 1 to 8. In someother implementations, the first SUL-related factor (and/or the secondSUL-related factor) and the minimum required received level factor mayfall in different value ranges.

In some implementations of the present disclosure, the UE may transmitan RRC system information request message to the base station when theUE does not receive a second SUL-related factor (e.g., theq-RxLevMin-sul value defined in the SIB2/SIB4 format) in other systeminformation.

In some implementations of the present disclosure, the UE may receive asecond SUL-related factor in inter-RAT cell reselection information insystem information from the base station, obtain a second minimumrequired received level based on the second SUL-related factor when theUE supports an SUL frequency on an inter-RAT cell, determine a secondcell selection criterion based on the second minimum required receivedlevel, and perform inter-RAT cell reselection based on the second cellselection criterion.

FIG. 5 is a block diagram illustrating a node for wirelesscommunication, in accordance with various aspects of the presentapplication. As shown in FIG. 5 , a node 500 may include a transceiver520, a processor 528, a memory 534, one or more presentation components538, and at least one antenna 536. The node 500 may also include an RFspectrum band module, a BS communications module, a networkcommunications module, and a system communications management module,Input/Output (I/O) ports, I/O components, and power supply (notexplicitly shown in FIG. 5 ). Each of these components may be incommunication with each other, directly or indirectly, over one or morebuses 540. In one implementation, the node 500 may be a UE or a BS thatperforms various functions described herein, for example, with referenceto FIGS. 1 through 4 .

The transceiver 520 having a transmitter 522 (e.g.,transmitting/transmission circuitry) and a receiver 524 (e.g.,receiving/reception circuitry) may be configured to transmit and/orreceive time and/or frequency resource partitioning information. In someimplementations, the transceiver 520 may be configured to transmit indifferent types of subframes and slots including, but not limited to,usable, non-usable, and flexibly usable subframes and slot formats. Thetransceiver 520 may be configured to receive data and control channels.

The node 500 may include a variety of computer-readable media.Computer-readable media may be any available media that may be accessedby the node 500 and include both volatile (and non-volatile) media andremovable (and non-removable) media. By way of example, and notlimitation, computer-readable media may include computer storage mediaand communication media. Computer storage media may include bothvolatile (and/or non-volatile), as well as removable (and/ornon-removable) media implemented in any method or technology for storageof information such as computer-readable instructions, data structures,program modules or data.

Computer storage media includes RAM, ROM, EEPROM, flash memory or othermemory technology, CD-ROM, Digital Versatile Disks (DVD), or otheroptical disk storage, and/or magnetic cassettes, magnetic tape, magneticdisk storage, or other magnetic storage devices. Computer storage mediadoes not comprise a propagated data signal. Communication mediatypically embodies computer-readable instructions, data structures,program modules or other data in a modulated data signal such as acarrier wave or other transport mechanism and includes any informationdelivery media. The term “modulated data signal” means a signal that hasone or more of its characteristics set or changed in such a manner as toencode information in the signal. By way of example, and not limitation,communication media may include wired media such as a wired network ordirect-wired connection, and wireless media such as acoustic, RF,infrared, and other wireless media. Combinations of any of the aboveshould also be included within the scope of computer-readable media.

The memory 534 may include computer-storage media in the form ofvolatile and/or non-volatile memory. The memory 534 may be removable,non-removable, or a combination thereof. Example memory includessolid-state memory, hard drives, optical-disc drives, etc. Asillustrated in FIG. 5 , the memory 534 may store computer-readable andcomputer-executable instructions 532 (e.g., software codes) that areconfigured to, when executed, cause the processor 528 to perform variousfunctions described herein, for example, with reference to FIGS. 1through 4 . Alternatively, the instructions 532 may not be directlyexecutable by the processor 528 but be configured to cause the node 500(e.g., when compiled and executed) to perform various functionsdescribed herein.

The processor 528 (e.g., having processing circuitry) may include anintelligent hardware device, e.g., a Central Processing Unit (CPU), amicrocontroller, an ASIC, etc. The processor 528 may include memory. Theprocessor 528 may process the data 530 and the instructions 532 receivedfrom the memory 534, and information through the transceiver 520, thebaseband communications module, and/or the network communicationsmodule. The processor 528 may also process information to be sent to thetransceiver 520 for transmission through the antenna 536, to the networkcommunications module for transmission to a core network.

One or more presentation components 538 presents data indications to aperson or other device. Examples of presentation components 538 mayinclude a display device, speaker, printing component, vibratingcomponent, etc.

From the above description, it is manifested that various techniques maybe used for implementing the concepts described in the presentapplication without departing from the scope of those concepts.Moreover, while the concepts have been described with specific referenceto certain implementations, a person of ordinary skill in the art mayrecognize that changes may be made in form and detail without departingfrom the scope of those concepts. As such, the described implementationsare to be considered in all respects as illustrative and notrestrictive. It should also be understood that the present applicationis not limited to the particular implementations described above, butmany rearrangements, modifications, and substitutions are possiblewithout departing from the scope of the present disclosure.

What is claimed is:
 1. A User Equipment (UE), comprising: one or morenon-transitory computer-readable media storing computer-executableinstructions; and at least one processor coupled to the one or morenon-transitory computer-readable media, and configured to execute thecomputer-executable instructions to: receive first other systeminformation from a base station, wherein other system informationcomprises system information other than minimum system informationbroadcast by the base station; determine whether a Supplementary Uplink(SUL)-related factor is present in the first other system information;transmit a Radio Resource Control (RRC) system information requestmessage to the base station in response to determining that theSUL-related factor is absent in the first other system information;determine a minimum required received level based on the SUL-relatedfactor in a case that the UE receives the SUL-related factor in secondother system information from the base station; and determine a cellselection criterion based on the minimum required received level.
 2. TheUE of claim 1, wherein the at least one processor is further configuredto execute the computer-executable instructions to: receive theSUL-related factor in intra-frequency cell reselection information in aSystem Information Block 2 (SIB2) of the second other system informationfrom the base station.
 3. The UE of claim 2, wherein the at least oneprocessor is further configured to execute the computer-executableinstructions to: perform an intra-frequency cell reselection procedurebased on the cell selection criterion.
 4. The UE of claim 1, wherein theat least one processor is further configured to execute thecomputer-executable instructions to: receive the SUL-related factor ininter-frequency cell reselection information in a System InformationBlock 4 (SIB4) of the second other system information from the basestation.
 5. The UE of claim 4, wherein the at least one processor isfurther configured to execute the computer-executable instructions to:perform an inter-frequency cell reselection procedure based on the cellselection criterion.
 6. The UE of claim 1, wherein the at least oneprocessor is further configured to execute the computer-executableinstructions to: receive the SUL-related factor in inter-Radio AccessTechnology (inter-RAT) cell reselection information in the second othersystem information from the base station.
 7. The UE of claim 6, whereinthe at least one processor is further configured to execute thecomputer-executable instructions to: perform an inter-RAT cellreselection procedure based on the cell selection criterion.
 8. A methodperformed by User Equipment (UE) for wireless communications, the methodcomprising: receiving first other system information from a basestation, wherein other system information comprises system informationother than minimum system information broadcast by the base station;determining whether a Supplementary Uplink (SUL)-related factor ispresent in the first other system information; transmitting a RadioResource Control (RRC) system information request message to the basestation in response to determining that the SUL-related factor is absentin the first other system information; determining a minimum requiredreceived level based on the SUL-related factor in a case that the UEreceives the SUL-related factor in second other system information fromthe base station; and determining a cell selection criterion based onthe minimum required received level.
 9. The method of claim 8, furthercomprising: receiving the SUL-related factor in intra-frequency cellreselection information in a System Information Block 2 (SIB2) of thesecond other system information from the base station.
 10. The method ofclaim 9, further comprising: performing an intra-frequency cellreselection procedure based on the cell selection criterion.
 11. Themethod of claim 8, further comprising: receiving the SUL-related factorin inter-frequency cell reselection information in a System InformationBlock 4 (SIB4) of the second other system information from the basestation.
 12. The method of claim 11, further comprising: performing aninter-frequency cell reselection procedure based on the cell selectioncriterion.
 13. The method of claim 8, further comprising: receiving theSUL-related factor in inter-Radio Access Technology (inter-RAT) cellreselection information in the second other system information from thebase station.
 14. The method of claim 13, further comprising: performingan inter-RAT cell reselection procedure based on the cell selectioncriterion.
 15. A base station, comprising: one or more non-transitorycomputer-readable media storing computer-executable instructions; and atleast one processor coupled to the one or more non-transitorycomputer-readable media, and configured to execute thecomputer-executable instructions to: transmit first other systeminformation to a User Equipment (UE), causing the UE to determinewhether a Supplementary Uplink (SUL)-related factor is present in thefirst other system information, wherein other system informationcomprises system information other than minimum system informationbroadcast by the base station; cause the UE to transmit a Radio ResourceControl (RRC) system information request message to the base station bynot including the SUL-related factor in the first other systeminformation; receive the RRC system information request message from theUE; transmit second other system information comprising the SUL-relatedfactor to the UE in response to receiving the RRC system informationrequest message; and cause the UE to determine, based on the SUL-relatedfactor, a minimum required received level for determining a cellselection criterion.
 16. The base station of claim 15, wherein theSUL-related factor is transmitted in intra-frequency cell reselectioninformation in the second other system information.
 17. The base stationof claim 16, wherein the second other system information comprises aSystem Information Block 2 (SIB2) that includes the intra-frequency cellreselection information.
 18. The base station of claim 15, wherein theSUL-related factor is transmitted in inter-frequency cell reselectioninformation in the second other system information.
 19. The base stationof claim 18, wherein the second other system information comprises aSystem Information Block 4 (SIB4) that includes the inter-frequency cellreselection information.
 20. The base station of claim 15, wherein theSUL-related factor is transmitted in inter-Radio Access Technology(inter-RAT) cell reselection information in the second other systeminformation.